A liquid crystal display (LCD) device includes an LCD panel and a backlight unit. A typical backlight unit uses a light emitting diode (LED) lightbar as light source and uses an LED backlight driving circuit to drive the LED lightbar to display. As shown in FIG. 1, the typical LED backlight driving circuit includes an LED lightbar 20, a power supply 10 driving the LED lightbar 20 to display, and a constant current driving chip 30 controlling the power supply 10 and the LED lightbar 20. The constant current driving chip 30 includes an adjusting unit 32 that adjusts brightness of the LED lightbar 20. An input end of the adjusting unit 32 is connected with a cathode of the LED lightbar, and an output end of the adjusting unit 32 is coupled to a ground terminal of the LED backlight driving circuit through a resistor.
When any one of LED lamps of the LED lightbar 20 short-circuits, temperature of the constant current driving chip 30 increases, thus the affecting stability of an entire LED backlight driving circuit.